Energy spectrum of ground state and excitation spectrum of quasi-particle for hard-core boson in optical lattices

We investigate the energy spectrum of ground state and quasi-particle excitation spectrum of hard-core bosons, which behave very much like spinless noninteracting fermions, in optical lattices by means of the perturbation expansion and Bogoliubov approach. The results show that the energy spectrum has a single band structure, and the energy is lower near zero momentum; the excitation spectrum gives corresponding energy gap, and the system is in Mott-insulating state at Tonks limit. The analytic result of energy spectrum is in good agreement with that calculated in terms of Green's function at strong correlation limit.

盐对菠菜叶绿体PSI光合电子传递及低温荧光发射光谱的影响

本文报告了以下几点研究所结果 1、NaCl， K2SO4等几种盐对菠菜叶绿体和PSI颗粒的甲基紫精光还原速率都有明显的促进作用。 2、以上几种盐都能改变叶绿体和PSI颗粒的低温荧光发射光谱中不同的荧光发射峰之间的比值。但是PSI颗粒低温荧光光谱的变化是和叶绿体低温荧光光谱的变化是不同的。 3、胰蛋白酶予处理并不能消除盐对叶绿体甲基紫精光还原反应的促进作用，相反地，却能提高盐的促进作用的灵敏度。 4、胰蛋白酶予处理也不能改变盐对叶绿体和PSI颗粒的低温荧光光谱的影响。 本文根据以上实验结果并结合前人的工作，对以上实验结果之间的内在联系进行了讨论，并试图说明盐在以上实验过程中的作用。

高等植物PSI ,PSII反应中心及天线系统色素蛋白复合体结构与功能的研究

一、实验证明了Cd H、Mg“在小麦类囊体膜上色素蛋白复合体的解聚和再聚合过程中，具有不同的作用。因此，二阶阳离子对激发能在光系统间的分配调节作用，可能不能仅仅用“静电现象”(Barber(1980))去解释。分析表明，在Ca2+作用下与PSII内周天线CP-47，GP-43多肽结合的L H C II和LHClb是来自间质膜区的PS I系统的。从PSI迁移到P S II的捕光色素蛋白，增加了PSII的捕光截面，从而促进了激发能有利于PsII分配。 二、Ca2*、Mg2+对小麦和菠菜类囊体膜光谱性质的影响有所差异。Ca2+对小麦类囊体膜光谱性质的影响还可以随着介质中Ca2+的消除而消除。同小麦类囊体膜相比，菠菜PSII以及LHCII更为集中在基粒区域，这可能是菠菜类囊体膜强Fv以及高F888／F735，F89H／F735比值的原因。因此，Ca2+，HgH对激发能在光系统间分配的调节作用是依赖于光系统间激发能及天线色素蛋白的分配状况的。 三、对菠菜叶中分离的PSII-RC: D1-D2-cyt b55g复合物进行的低温荧光发射光谱的研究表明，这一复合物可能具有F681和F684两种波长的低温荧光发射，但它们通常并不是同时存在，而是取决于Ca-670与Ca-680 Chla分子的相对含量的。PSII-RC内周无线GP-47，GP-43多肽的存在是D1-D2-cyt b559复合物低温荧光发射红移的原因;而D1一D2cyt b559复合物的不稳定性则与其低温荧光发射的蓝移现象有关。 从蕹菜叶中分离的Dl—D2-cyt b559复合物的F 381低温荧光发射也是由其相对含量较高的C．i-6 7 0 Chla分子的存在决定的。对蕹菜D 1一D 2-cyt b559复合物中的分析还表明，F 681的低温荧光发射直接来源于Di／D2复合物，而415nm处相对较强的吸收，则可能主要是与Pheo的存在有关的。 四、多肽分析与光谱分析的对照表明，CP-26内周天线多肽可能是PSII中F695低温荧光发射的真正来源。 五、实验分析了蔗糖密度离心分离的LHClI和PSI颗粒。结果排除了CP-27多肽（以及CP，一2 5，GP-47，CP -4 3多肽）具有F695低温荧光发射的可能，因此支持了CP-26多肽是PSII中F695低荧光发射来源的看法。对PsI颗粒的分析表明，P700的存在可能是与PSI-RC中较大的Sub-I亚基相联系的。 六、根据以上的研究结果，提出了PSI，PSII在类囊体膜上的结构模式，并对其内容进行了分析和讨论。

PCDD/F-s, PCBs, HCHs and HCB in sediments and soils of Ya-Er lake area in China: Results on residual levels and correlation to the organic carbon and particle size

Sediments and soils collected from the Ya-Er Lake area in China were analysed for the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyl (PCBs), hexachlorocyclohexane (HCHs) and hexachlorobenzene (HCB). The results indicated the main pollution problems in the Ya-Er Lake area, which was heavily polluted by HCHs and chlorobenzenes, now is dominantly polluted by PCDD/Fs, PCBs and HCB. The occurrence of PCDD/Fs and PCBs with relatively high levels of HpCDDs, OCDD and low chlorinated-substituted PCBs, is attributed to the discharge of waste water and biodegradation. The vertical distributions of HCH-residues are related with the content of organic carbon and particle size. Copyright (C) 1996 Elsevier Science Ltd

Collective and single-particle excitations in coupled quantum wires in magnetic fields

The full spectra of magnetoplasmons and single-particle excitations are obtained of coupled one-dimensional electron gases in parallel semiconductor quantum wires with tunneling. We show the effects of the interwire Coulomb interaction and the tunneling, as well as the magnetic-field-induced localization on the elementary excitations in symmetric and asymmetric coulped quantum wire structures. The interacton and resonance between the plasmon and the intersubband single-particle excitations are found in magnetic fields.

An Enhanced Particle Swarm Optimization Algorithm

Particle Swarm Optimization (PSO) algorithm is often used for finding optimal solution, but it easily entraps into the local extremum in later evolution period. Based on improved chaos searching strategy, an enhanced particle swarm optimization algorithm is proposed in this study. When particles get into the local extremum, they are activated by chaos search strategy, where the chaos search area is controlled in the neighborhood of current optimal solution by reducing search area of variables. The new algorithm not only gets rid of the local extremum effectively but also enhances the precision of convergence significantly. Experiment results show that the proposed algorithm is better than standard PSO algorithm in both precision and stability.